package com.wj.facedetect;import android.content.Context;import android.support.test.InstrumentationRegistry;import android.support.test.runner.AndroidJUnit4;import org.junit.Test;import org.junit.runner.RunWith;import static org.junit.Assert.*;/** * Instrumented test, which will execute on an Android device. * * @see <a href="http://d.android.com/tools/testing">Testing documentation</a> */@RunWith(AndroidJUnit4.class)public class ExampleInstrumentedTest {    @Test    public void useAppContext() {        // Context of the app under test.        Context appContext = InstrumentationRegistry.getTargetContext();        assertEquals("com.wj.facedetect", appContext.getPackageName());    }}